flour

Types of wheat flour

When a recipe calls for flour it usually means wheat flour, unless otherwise stated. (Common types of non-wheat flour include buckwheat flour, cornflour, potato flour, rice flour, spelt, chickpea flour - indeed, almost anything with a high starch content can be made into flour.)

Under the umbrella of wheat flour there are a variety of products which have different properties, each resulting in a different outcome when cooking.

Main groups

• Wholemeal flour / wholewheat flour / Graham flour - made from 100% of the grain
• Brown flour - 10-15% of the grain removed (as bran)
• White flour - up to 30% of the grain removed (the bran, wheatgerm and some minerals)

Sub-groups of wheat flour

The 2 main proteins are gliadin and glutenin and these become gluten once water is added to the flour in a recipe. Most commercial flours contain a mixture of different varieties of wheat, blended to produce the required characteristics.

Gluten provides a strengthening network within the basic structure of the finished product, and the more the flour mixture is handled, the more gluten is released. Too much gluten results in stiff, heavy cakes and pastry, which is why you need to use a low protein type flour for these, and why handling should be kept to a minimum during mixing.

A strong gluten network is essential for well risen bread, therefore strong flour is a must; heavy kneading draws out more gluten, and the process may be further enhanced by the addition of ascorbic acid and salt.

• soft flour / weak flour / cake flour - 8% protein
• plain flour / all purpose flour / self raising flour - 10% protein
• strong flour /bread flour /hard wheat flour / high gluten flour - 11 to 17% protein
• gluten flour (different from high gluten flour) - (most of the starch and bran is removed) 45% protein

Flour as a thickening agent

As well as being the primary ingredient in bread, cakes, cookies, pasta etc, flour is often added to liquids as a thickening agent. It is the starch which is responsible for thickening. When the starch granules are heated in a liquid, they swell and eventually burst, releasing starch. The starch forms a molecular network which traps and absorbs water, thereby thickening the mixture.

Tip: never, ever lick the spoon and put it back into the sauce! As well as being unhygienic, saliva contains an enzyme (amylase) which breaks down the starch network - your thickened sauce will rapidly become runny again and there's nothing you can do to save it.

Nutritional value

Flour provides 310 - 340 kcal/100g (1320 - 1450 KJ/100g) depending on the type. It provides protein, a range of vitamins, particularly the B vitamins thiamin and niacin, and a range of minerals. It is low in fat.

http://www.nutrition.org.uk/Facts/commodities/flour.html
http://www.wheatintolerance.co.uk/generalfaq.asp

Flour (?), n. [F. fleur de farine the flower (i.e., the best) of meal, cf. Sp. flor de la harina superfine flour, Icel. flur flower, flour. See Flower.]

The finely ground meal of wheat, or of any other grain; especially, the finer part of meal separated by bolting; hence, the fine and soft powder of any substance; as, flour of emery; flour of mustard.

Flour bolt, in milling, a gauze-covered, revolving, cylindrical frame or reel, for sifting the flour from the refuse contained in the meal yielded by the stones. -- Flour box a tin box for scattering flour; a dredging box. -- Flour dredge ∨ dredger, a flour box. -- Flour dresser, a mashine for sorting and distributing flour according to grades of fineness. -- Flour mill, a mill for grinding and sifting flour.

© Webster 1913.

Flour, v. t. [imp. & p. p. Floured (?); p. pr. & vb. n. Flouring.]

1.

To grind and bolt; to convert into flour; as, to flour wheat.

2.

To sprinkle with flour.

© Webster 1913.